So I know that the OEM versions of Windows you can buy are licensed to only be installed on a single computer, but as someone who regularly upgrades individual components in my PC, what constitutes the same computer is a bit of a gray area. I personally have been able to install Windows 7 OEM on a new hard drive in my computer, and though I had to call Microsoft's activation phone number, it worked fine. However, I have heard that upgrading certain components will cause problems with OEM versions. Has anyone tried replacing their motherboard with OEM Windows? The CPU? I'm just wondering if there's any real reason to go with the retail Windows, or if it's just to get more money out of people who don't know better.

As far as Microsoft is concerned, if you get a new motherboard you get a new PC. OEM licences aren't transferable between PCs therefore replacing your motherboard invalidates your licence. The only exception to this is if you replace your motherboard due to it being faulty. Reference: http://download.microsoft.com/download/ ... slicqa.doc

11. Rather than purchase completely new PCs, my organization performs in-place upgrades to the hardware on many of our computers. We often times only replace the motherboard, processor, and memory. Since the COA is still on the case and the OS is still installed on the hard drive, this computer is still licensed, right?

ANSWER. Generally, you may upgrade or replace all of the hardware components on your computer and maintain the license for the original Microsoft OEM operating system software, with the exception of an upgrade or replacement of the motherboard. An upgrade of the motherboard is considered to result in a "new personal computer." Microsoft OEM operating system software cannot be transferred from one computer to another. Therefore, if the motherboard is upgraded or replaced for reasons other than a defect then a new computer has been created, the original license expires, and a new full operating system license (not upgrade) is required. This is true even if the computer is covered under Software Assurance or other Volume License programs.

You may be able to sweet talk the agent on the other end of the activation line into reactivating your OS but I wouldn't count on it!

I believe the NIC is also given extra weight in the "has this computer changed" determination. Of course, given that most NICs are on the motherboard these days this distinction has become much less important.

That said, I have successfully swapped out dead motherboards and had no issues (not even requiring a phone call), so the rules apparently aren't hard and fast, even for automatic Internet activation. IIRC there's a timer -- after a certain number of months, they relax the criteria for requiring a phone call or (worst case) new license.

Caveat: My experience has been with XP; no idea if the rules are the same for Vista/7.

What does ‘substantially the same’ mean? WPA asks for ‘votes’ from each of these ten categories: ‘Is the same device still around, or has there never been one?’ Seven Yes votes means all is well — and a NIC, present originally and not changed, counts for three yes votes! Minor cards, like sound cards, don’t come into the mix at all. If you keep the motherboard, with the same amount of RAM and processor, and an always present cheap NIC (available for $10 or less), you can change everything else as much as you like.

In other words, you can change three components besides the NIC (since everything else gets only one vote) without freaking out WPA. After 120 days with no further changes, this becomes the new "normal" for the system and you can make further changes without reactivating.

But like just brew it!, I don't know if Vista/7 change this. I suspect not.

FuturePastNow wrote:...In other words, you can change three components besides the NIC (since everything else gets only one vote) without freaking out WPA. After 120 days with no further changes, this becomes the new "normal" for the system and you can make further changes without reactivating.

I wonder if that 120 day reset is the same reset that determines whether an automatic reactivation attempt (say you decide to do a "nuke from orbit" reinstall) goes through...

From recent experience I had to replace a crispy motherboard in a friend's PC, it had an OEM Vista Home Premium install. I had to totally re-install Vista and phone activate it, but other than that no problem. I'd say it's no big deal.

Well, I guess that explains why I was confused about it, if the rules they have aren't applied 100%. Just for clarification, I'm not actually planning on replacing my motherboard anytime soon, by the time I do, Windows 8 might be out anyway.

I've done the phone activation, too, and had no problem. Specifically, I built a Windows Home Server I was unhappy with, then completely rebuilt it (everything new except the RAM). Had to call MS to reuse the WHS key. No questions asked.